The embodiments described herein relate generally to simulations within a product lifecycle management (PLM) system and, more particularly, to determining and managing behavioral tolerances of the virtual prototypes managed within a PLM system.
Today's complex systems are required to meet hundreds of top level product acceptance requirements which, in turn, reference numerous standards and sub-requirements. Because of the infinite number of failure modes of systems that include both computational and physical elements, there is a need to express requirements in terms of probabilities.
Certification of probabilistic requirements involves both verification and validation. Verification is the process used to determine whether the right processes were used to build a product. Validation is the process of establishing evidence that the product meets the customer's requirements. A large variety of techniques are used today to certify cyber physical system requirements. Examples are reachability and fault tree analysis, Monte Carlo simulation, virtual prototyping, as well as quality assurance processes used in software development based on mean time between failure, defect density, and other metrics.
Many product development processes attempt to use only physical prototypes to certify a design. However, and especially in the early stages of design, physical prototypes will likely not be available. This frequently leads to multiple prototype changes during certification that could have been avoided if the prototypes could be simulated to a known accuracy. Later in the life cycle, but before product launch designers may rely on simulated behavior because it is not feasible to carry out physical experiments of, for example, very large scale projects such as aircraft, cargo ships, or ocean-bound oil rigs. Even after a product is operational, the designers may still have to carry out virtual product certification. The configuration and/or mission of the product may change and the designers will likely want to know if the product can be certified for a new mission. At that point the designers will also have measured operational data for the product which can be used to improve the fidelity of the virtual prototypes.